Fuel injector timing ?

[80broncoman]

If it was possible to alter fuel injector timing on sequential injected engine, any idea which way to go? I am sure the lower the rpm the more gain could be seen. I am sure at higher rpm 2000 and higher at wot there would no difference. I am looking to gain low end grunt around 1000 to 1600 rpm.
I think you would want the fuel injected just before the air pulse gets to it to shove it in the head.
Am I thinking correctly?

 

[Anonymous]

Are you thinking similar to changing ignition timing to get a better low end torque curve?

I dont know what would happen if you altered the tone wheel on the crank and cam a little bit. If you could, it would be just a hair off from the default factory setting.

I think it is too far of a stretch to go to get some more low end unless your purpose states otherwise. Like a half a second in the 1/4 mile?..i dunno...sounds too much work for something that may not change it enough to matter.

 

[MustangSix]

Injector pulsewidth controls the amount of fuel that gets squirted. Pulse it longer, you get more fuel.

I'm not sure that adding more fuel will give you more power. The real key to making more power is airflow. Unless you had a less restrictive intake and exhaust which supported more air coming into the engine, more fule would not help much. And the stock system will compensate with additional fuel, to a point, whenever more air is available.

 

[Lazy JW]

At what time is the fuel actually injected on the EFI 300? I know that some engines squirt the fuel when the intake valve is CLOSED allowing the fuel to soak heat from the valve and partiall vaporize. Then when the valve opens the fuel gets pulled in. The early VW air-cooled FI engines squirted two cylinders at the same time. It really doesn't sit there very long when you think about it. I suspect there wouldn't be much gain from altering the injector timing, but that is just a guess.
Joe

 

[MustangSix]

I think the later Ford systems are sequential, injecting fuel that is timed with an intake event. But sequential systems often revert to a batch fire strategy at higher speeds because a. the injector pulsewidth gets longer, and b. the time to inject gets shorter. At some point the two timelines intersect, making SEFI irrelevant. That's usually not a very high rpm.

My SDS is a batch fire, pulsing twice per revolution. SEFI would be more efficient at low speed and at idle, and would have better emissions.